In this study, a laser sheet technique and PLIF (Planar laser-induced fluorescence) are applied to a laboratory-scale pulverized coal burner of the open type, and the spatial relationship of the pulverized coal particle zone and the combustion reaction zone is examined by simultaneous measurement of Mie scattering and OH-LIF images. It is found that this technique can be used to investigate the spatial relationship of the combustion reaction zone and pulverized-coal particles in turbulent pulverized-coal flames without disturbing the combustion reaction field. In the upstream region, the combustion reaction occurs only in the periphery of the clusters where high-temperature burned gas of the methane pilot flame is entrained and oxygen supply is sufficient. In the downstream region, however, combustion reaction can be seen also within clusters of pulverized-coal particles, since the temperature of pulverized-coal particles rises, and the mixing with emitted volatile matter and ambient air is promoted.

The world consumption of the coal has been increased very sharply during past few years result from oil exhaustion, fluctuation in the price of oil and low price competitiveness of alternative energy. The International Energy Agency (IEA) has estimated that coal will be available for over 110 years, with coal reserves of close to 860 billion tons. The pulverized coal is blended coal powder that the particle diameter under 10μm. It has advantage of combustion efficiency and flame stabilization. The use of coal blends is becoming increasingly common in pulverized-coal power plants because it improves the economic performance of these plants by diversifying the fuel range. However, although blending can improve combustion behaviors and decrease gaseous pollutant emissions, it has difficulty of design and operating the pulverized coal combustor because despite the small particle size, combustion process of pulverized coal is exceedingly complex. Because of that the detail study on the combustion characteristic is important for increasing of efficiency. As a base investigation for numerical calculation of pulverized coal combustion, this study verified validity of models and compare the numerical calculation results with the experimental results.